This application relates generally to systems and methods for providing arc fault and/or ground fault protection for distributed generation sources.
In recent years, rising utility costs and growing concern regarding environmental harm caused by use of fossil fuels has spurred enhanced interest in “alternative” energy supplies, such as solar, wind, and hydroelectric power sources. In addition, as the cost of alternative energy sources has decreased, and as more electric utilities offer grid connected “net metering” programs that allow system owners to feed surplus electric power back to the electric utility, the use of alternative energy sources has increased.
In a conventional residential net metering solar system, one or more photovoltaic panels are used to convert solar energy to a DC current, and one or more inverters convert the DC current to an AC current synchronized to the magnitude, phase and frequency of the voltage signal supplied by the electric utility. In a majority of installations, the generated AC signal is then fed into the home power distribution system (e.g., a circuit breaker panel) typically by back-feeding one or more conventional circuit breakers.
A conventional circuit breaker typically is an electro-mechanical device that provides overload and short-circuit protection, but does not provide arc fault or ground fault protection. As a result, the wiring extending between the inverter and the home power distribution system is not protected against arc faults, but is capable of being subjected to such faults.
Some previously known distributed generation sources have included arc fault and/or ground fault protection at or near the power sources, which are typically located on the roof of a building or at another location far away from the electrical panel. However, such sources typically are remotely located, often in severe weather environments, that are not always easy or convenient to access. As a result, such remotely-located arc fault and/or ground fault protection devices can be difficult to reset, maintain and replace.
Accordingly, improved arc fault and/or ground fault protection for distributed generation sources is desirable.